Iraq's government is fighting a rebellion which has
seen it rapidly lose control of predominantly Sunni
Arab northern and western parts of the country.

The militant group Isis is widely perceived as leading
the uprising, but it is not acting alone.

Here, jihadist groups analyst Aymenn Jawad Al-Tamimi
looks at who is taking part in the insurgency.

ISLAMIC STATE IN IRAQ AND THE LEVANT
(ISIS)

While Isis has grabbed headlines around the world,
there can be a tendency to overstate its role in the
insurgency.

Indeed, initial media coverage of events like the fall
of Falluja and Mosul often portrayed the insurgent
offensives as solely the work of Isis. The perception
is fed by Isis' social media output that puts great
weight on holding parades and raising the banner in
assertions of power.

However, it cannot be denied that Isis is at least
leading the majority of moves into new territory to
wrest control from government forces. This is partly
because Isis is better equipped, having seized
advanced weaponry and uniforms from security forces
over the past couple of years.

Furthermore, when it comes to asserting authority in a
new area, one advantage Isis has over other groups is
its superior financial resources, which enable it to
engage in outreach to locals.

It is this outreach, combined with the group's
restrained conduct in Falluja, that gives Isis an
advantage in securing tribal support in Anbar in
particular, where some negotiated handovers of
territory to Isis' authority have taken place and
where hope has been expressed that Isis will not be
harsh in imposing its strict view of Islamic law on
the tribes.

One of Isis' slogans is "remain and expand", which is
precisely what it has done in Syria and Iraq.

In Iraq, Isis has a presence in most of the localities
that have fallen into insurgent hands, spearheading
the takeovers of Mosul and Tikrit.

In both cities, Isis has asserted itself as the main
authority. Indeed, from the "city charter" issued by
Isis for Mosul, the group has made it clear it wishes
to turn Mosul into Iraq's version of the city of Raqqa,
its de facto capital.

Conversely in Falluja, Isis has not issued a similar
charter and has been more tolerant of practices it
deems un-Islamic, illustrating that it still does not
exercise full control over the city and has to share
power with a military council composed of a variety of
insurgent groups in the wider area, backed by tribal
support.

Estimates for Isis' numerical strength in Iraq range
from just 2,000-3,000 to perhaps 10,000 or more.
Considering the sheer number of operations Isis has
been able to carry out in comparison with other
groups, the higher end estimates seem more plausible.

JAMAAT ANSAR AL-ISLAM (JAI)

JAI is a rival of Isis and is primarily based in
Nineveh (particularly Mosul), Kirkuk and Salahuddin
provinces, though its numerical strength is not known.
While JAI shares Isis' aspirations for a caliphate, it
rejects Isis' claim to represent an actual state
rather than a mere group.

JAI and Isis fought one another throughout last year
because of a dispute stretching back to Isis' previous
incarnation as the Islamic State in Iraq (ISI).

Since the outbreak of the insurgency in Anbar province
in December 2013, some fighters have taken up the JAI
banner in the Falluja area, and more recently the
group claimed a role in the fall of Tikrit.

Rumours have since emerged of the arrest and killing
by Isis of multiple JAI members in Mosul and Tikrit.
In Mosul, dozens of JAI members have pledged
allegiance to Isis rather than resist.

NAQSHBANDI ORDER

While exact numbers are difficult to determine,
the Army of the Men of the Naqshbandi Order (Jaysh
Rijal al-Tariqa al-Naqshbandia, or JRTN) and its front
groups likely constitute the second largest insurgent
grouping in Iraq after Isis.

Led by Saddam Hussein's right-hand man, Izzat Ibrahim
al-Douri, JRTN is the main front for Baathist
insurgents. JRTN espouses a blend of the banned
Baathist Party's ideology (pan-Arab, secular
nationalism) and Naqshbandi Sufi Islam, while
emphasising the language of jihad in an attempt to
garner religious legitimacy.

As most Sunni Arabs are not Naqshbandis, JRTN set up
front groups of Baathists, which have become unified
under the "General Military Council for Iraq's
Revolutionaries" (GMC).

Though co-ordination with Isis is not admitted, it is
apparent that JRTN and its front groups have worked
with Isis not only in Mosul but also in Tikrit and
Diyala province.

Such co-operation suggests JRTN hopes for some kind of
power-sharing arrangement that could eventually get
the better of Isis and lead to a restoration of the
Baathist state, as existed under Saddam.

In public statements, JRTN tries to avoid mentioning
Isis by name and it is clear that there is no wish to
engage in an all-out war against Isis, though on both
sides there is profound distrust on account of
ideological differences.

The JRTN's front group, the GMC, also operates in the
remaining parts of Anbar still contested with
government forces, such as Ramadi and Karma, and
maintains a presence in Falluja.JAYSH AL-MUJAHIDEEN (JAM)

A group dating back to the 2003 invasion, JAM
aspires to overthrow the central government and is
anti-Shia in outlook.

Recent evidence suggests it has forged a special
relationship with JAI as a counter to Isis, which JAM
deems extremist, and there have been indications of
co-ordination in the Hawija area, near Kirkuk city.

JAM also places emphasis on working with local tribes,
and appears to be maintaining a strong presence in
Karma. However, tensions have emerged there with Isis
over allegations that the jihadist group has been
attempting to gain a monopoly on the movement of
commodities, though there have been no reports of
actual infighting yet.

ISLAMIC ARMY OF IRAQ (IAI)

Another traditional
insurgent brand, the IAI is distinguished from the
other groups in that after the US withdrawal at the
end of 2011, IAI formally demobilised and set up an
activist wing - the Sunni Popular Movement- aiming to
push for a Sunni Arab federal region.

On account of joining the political process, the IAI
is criticised by Jam, which denies any co-ordination.

Beginning with this year, however, the IAI has taken
up the cause of armed struggle again, with evidence of
the group's presence primarily emerging from Diyala
and Salahuddin provinces.

One should however be wary of spokesmen's spin about
having thousands of fighters under the banner. In
reality, the group was much weakened through
abandonment of the IAI for the Sahwa, or Awakening,
forces (anti-al-Qaeda Sunni militia) and the joining
of the political process.

As of now, the IAI effectively offers the choice to
the central government of either giving in to the
IAI's calls for a Sunni federal region or of preparing
for the capture of Baghdad.

Aymenn Jawad Al-Tamimi is a Shillman-Ginsburg
Fellow at the Middle East Forum who specialises in
jihadist groups in Syria and Iraq.